#let 字号 = (
  初号: 42pt,
  小初: 36pt,
  一号: 26pt,
  小一: 24pt,
  二号: 22pt,
  小二: 18pt,
  三号: 16pt,
  小三: 15pt,
  四号: 14pt,
  中四: 13pt,
  小四: 12pt,
  五号: 10.5pt,
  小五: 9pt,
  六号: 7.5pt,
  小六: 6.5pt,
  七号: 5.5pt,
  小七: 5pt,
)

#let 字体 = (
  宋体: ("Times New Roman", "SimSun"),
  黑体: ("Times New Roman", "SimHei"),
)

#let numbering = "1"
#let stroke = 0.01pt


#let main(it) = {
  set page(
    paper: "presentation-16-9",
    margin: 5%,
    footer: context [
      #set align(center)
      #set text(字号.四号)
      #counter(page).display("1 / 1", both: true)
    ]
  )
  set text(font: 字体.黑体, size: 字号.小二, lang: "zh")
  set par(first-line-indent: 0em, justify: true)
  show figure: it => {
    set align(center)
    set text(size: 字号.四号)
    show par: set block(spacing: 1em)
    set par(leading: 1em)

    v(1em)
    it.body
    v(1em)
    it.caption
  }
  set heading(numbering: numbering)
  show heading: it => {
    set text(font: 字体.黑体, weight: "light")
    if it.level == 1 {
      set text(stroke: stroke)
      underline(it.body, offset: 8pt)
    } else {
      set text(stroke: stroke)
      [#counter(heading).get().last(). #it.body]
    }
    v(0.2em)
  }

  it

  pagebreak()
  {
    set align(center)
    bibliography(
      "ref.bib",
      style: "gb-7714-2015-numeric",
    )
  }
}
